Apparatus for forming concrete piles



NOV. 15, 1932. R TADA APPARATUS FOR FORMING CONCRETE PILES Filed Jan. 19.

|||| IIIVWM Patented Nov. l5., T932.

UNITED STATES PATENT OFFICE RENZO TADA, OF TOKYO-FU, JAPAN, ASSIGNOR TO TOY() KOMPURESORU KABUSHIKI KAISHA (THE ORIENTAL COMPRESSOL CO. LTD.), OF TOKYO, JAPAN, A CORPORATION or JarAN APPARATUS FOR FOR-MING CONCRETE PILES Application led January 19, 1931, Serial No. 509,820, and in Japan February 24, 1930.

This invention relates to an apparatus for forming concrete piles, especially an apparatus for forming concrete piles having enlarged portions at intervals along the length of the piles to increase the supporting area thereof.

One of the objects of the invention is to supply charges of concrete at the centre of the stamping part so as to rend-er it suitable for the formation of aconcrete pile having enlarged portions evenly projected around the pile-body.

The other object of the invention is to strengthen the lower part of the inner tube for increasing the durability of the apparatus.

It has already been devised that an apparatus for forming a. concrete pile having enlargements at intervals along-its length comprises an outer and an inner tube, and the lower end of the inner tube is made in a conical shape composed of two halves, one of the said halves being integrally formed with the inner` tube-body` and the other being formed separate from the inner tube and adapted so as to slide along the first mentioned half of the conical end. In apparatus of this type, concrete material is charged at rst into the inner tube, and by pulling up one of the halves so as to slide along the other, there is formed between the halves an opening through whichV the concrete material contained in the inner tube is discharged to the bottom of a vertical hole where the concrete pile is formed. In this construction, the concrete material cannot be concentrated at the centre of the bottom of the hole, but has a tendency to accumulate on one side of the hole, whereby the enlargements formed by stamping the material cannot be co-aXially located with the pile-body. The main object of the present invention is to obviate such defect.

This invention essentially consists of an apparatus for forming concrete piles'of the type above referred to, wherein a sleeve naving a truncated conical hollow end is slidably arranged around the lower part of the inner tube, and the bottom members having a hollow semi-conical shape respectively are hinged on opposite sides 'ofthe lower end of the inner tube, the said bottom members being allowed toswing downwards by their own weight to open the lower end of the in-l ner tube as the said tube is raised, but being caused to close the lower end of the inner tube by co-operation with the inner wall of the tapered or conical end of the sleeve as the inner tube is lowered. n

An embodiment of this inventionis illustrated inthe drawing in which l Fig. l shows a longitudinal section of the apparatus, the upper part thereof being dispensed with.

Fig. 2 shows across section thereof.

Fig. 3 shows the manner of stamping and i tom members 4 having a hollow Lsemi-conical shape. On the inner tube l2, a ring 5 is attached anda sleeve 6 having an annular top closure is spaced apart from and arranged around the inner tube 2 so as to freely slide along the tube, the ring 5 serving as'an abutment for the-internal flange of the upper end of the sleeve to limit the upward movement of the inner tube relative to the sleeve. The lower part of sleeve 6 is tapered as shown at 7 and terminates to form an opening. When the inner tube v2 is lowered in relation to the sleeve 6, tips of the .swinging bottom lmembers 4 are caused to slide along the inner surface of the'tapered part 7 and to swing inwards. When the outer surfaces of the bottom members 4 are kbrought completely vinto contact with the inner surface of the tapered part, the bottom pieces are completely closed I and the pointed ends of the members project downwards through the sleeve. Thus the opening and closing operations of the bottom member. take placev automatically ina the inner tubes. 8 is a reinforcement shoe having a conical head. The reinforcement shoe 8, sleeve 6 and inner tube 2 can be lirmly connected by a detachable transverse pin 9 inserted through holes 9 provided in the shoe, sleeve and inner tube respectively, as shown in Fig. 4.

In operation, the outer tube l with the shoe piece 8, loosely fitted on its lower end and the inner tube 2 inserted in its bore, is driven by a steam hammer'into the ground to a desired depth where the concrete pile is to be formed. Then the inner tube with the sleeve 8 is' withdrawn from the outer tube and the material is charged into the outer tube. The inner tube With the sleeve and reinforcement shoe is in serted into the outer tube, and lowered so as to c'lose its lower end by the bottom members 4. The outer tube only'is at first raised a suitable distance,'the shoe piece 3 being left at the bottom of the hole. Then successive strong blows are given at the upper end of the inner tube by the steam hammer so as to stamp and squeeze the concrete material outwards for forming a spherically enlarged part as shown in F ig. 3. After the lowermost enlarged part has been formed, the outer tube is withdrawn for a distance corresponding to n the spacing between adjacent enlarged parts to be formed, and the inner tube 2 with the sleeve 6 only is inserted into the outer tube 1 till the end of the inner tube is closed by the hollow bottom, a ringattached on the outer surface of the inner tube and adapted to come into contact with the closure to limit the up- Ward movement of the inner tube relative to the sleeve, and hollow semi-conical bottom members pivoted on the lower end of the inner tube and adapted to automatically open the lower end of the inner tube during the upward motion of the inner tube and to close the lower end at the completion of the downward motion of the inner tube by cooperation with theinner surface of the truncated bottom of the sleeve.

In testimony whereof, I have signed my name to this specification at Tokyo, Japan, this 5th day of December, 1930.

. RENZO TADA.

bottom members l engaging with the conical Y bore of the sleeve 6. Then the material is charged into the inner tube from its top end, and the inner tube is slightly raised to open its lower end for discharging the material contained in the tube, and stamped by the steam hammer to form the body or cylindrical part of the pile. The concrete material supplied after the formation of the lowermost enlargement is stamped by the lower end of the inner tube and sleeve without the use of the shoe piece 8. The charge of the material into the hole and its stamping operation takes place alternately` while the outer tube is raised.

In this invention, as the hollow semi-conical pieces pivoted on the lower end of the inner tube are used in association with the sleeve for supplying and stamping the charge of concrete material, there are obtained advantages such that the lower end of the inner tube is reinforced and the concretematerial is always supplied at the centre or thereabouts of the part which is to be subjected to the stamping action, for evenly distributing the material around the axis of the pile to be formed.

I claim:

Apparatus for forming concrete piles having an outer tube, an inner tube, a sleeve Y spaced apart from and arranged around the lower part of the inner tube and provided with an annular top closure and a truncated 

